Vector Algebra - Online Test

Q1. Magnitude of the vector  is
Answer : Option B
Explaination / Solution:



Q2. Find the scalar and vector components of the vector with initial point (2, 1) and terminal point (– 5, 7).
Answer : Option C
Explaination / Solution:

The scalar and vector components of the vector with initial point (2, 1) and terminal point (– 5, 7) is given by : (- 5 – 2 ) i.e. – 7 and (7 – 1 ) i.e. 6. Therefore, the scalar components are – 7 and 6 .,and vector components are - 

Q3.

Find the values of x and y so that the vectors  are equal


Answer : Option C
Explaination / Solution:

  
x = 2, y = 3

Q4. Find the sum of the vectors 
Answer : Option C
Explaination / Solution:

We have:
vectors 


Q5. Write down a unit vector in XY-plane, making an angle of 30° with the positive direction of x-axis.
Answer : Option D
Explaination / Solution:

Let be a unit vector in XY plane,making angle 300 with positive X axis,so we have the vector as 

 is the required vector.

Q6. Find the value of x for which is a unit vector
Answer : Option D
Explaination / Solution:

As x is a unit vector ,
therefore,

Q7. Find the position vector of a point R which divides the line joining two points P and Q whose position vectors are  externally in the ratio 1 : 2. Also, show that P is the mid point of the line segment RQ.
Answer : Option C
Explaination / Solution:



Q8.
Answer : Option C
Explaination / Solution:

Let



Q9. The scalar product of the vector  with a unit vector along the sum of vectors  is equal to one. Find the value of.
Answer : Option A
Explaination / Solution:

Let  and 

Therefore, a unit vector along
 is given by:


Also, scalar product of  with above unit vector is 1.


Q10. The scalar product of two nonzero vectors   is denoted by
Answer : Option A
Explaination / Solution:

The scalar product of two nonzero vectors  is denoted by .and is defined by =